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Old 07-01-2006, 08:11 AM   #1
jschiwal
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Spam filters could do much better.


My ISP filters out spam. I don't get a lot, but I'm surprised at what gets through.

Here is one of seven lines from some spam that I received:
too happy but coat tongue must awake. are war the sort monkey as clean. and tooth but taste garden too stick. as smile must meeting

The rest of the lines are similar. An eliza<->zippy the pinhead dialog would make more sense. Apparently, the spam filter only uses lexical and statistical analysis. It would be nice if they would be able to spot when messages sent from the same place make no sense. A little AI please!

I don't understand what the purpose of sending such a message is, other than to use up bandwidth on the network. Are these people mentally ill?

Last edited by jschiwal; 07-01-2006 at 08:15 AM.
 
Old 07-01-2006, 12:25 PM   #2
spirit receiver
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I even received "spam" messages that were completely blank. The only reason I could think of is that someone might be checking for valid email addresses. Do they do this? Probably not, now that I think of it. Who should receive the delivery failure message, as the evil guys surely didn't put their own address into the message.

Surprisingly, SpamAssassin does a great job, even in these cases. I haven't had a single false classification for weeks.
 
Old 07-02-2006, 06:25 AM   #3
JunctaJuvant
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I also receive blank spam messages, but the spam message appears to be concealed in a bunch of .gif attachments (to prevent scanning I think). I am also using spamassassin, but I guess I need to tweak it a little more to get rid of these false-negatives.
As for the nonsense email snippet jschiwal posted: Maybe your ISP's scanner only detected a suspicious attachment, stripped that off and sent the body of the message through? Perhaps it contained a virus or worm?
 
Old 07-02-2006, 09:28 AM   #4
Hangdog42
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The bit I don't get is why the highly repetitive spam doesn't get picked up. Every day I get email from at least one person looking to move millions of dollars/rubles/pounds/euros/clamshells into my bank account. They are all so similar, I can't imagine why a spam filter doesn't pick it up.
 
Old 07-02-2006, 12:43 PM   #5
taylor_venable
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Most of the spam I get are composed of random words. I don't understand it either; but SpamAssassin has flagged every single one of them, so I don't have to read them. I guess that ISPs aren't as good catching this type of spam because it requires more complicated checking; it's not just a simple easy-to-spot advert. So to avoid wasting resources they probably just run the most basic tests and then send it on. I can aford a little more CPU time for SpamAssassin because there's not many users on my mail system.

What mystifies me is when I get spam via the ISP that has a subject like "Re: i l0v3 u", a blank body, and a JPEG image attachment. Sure, in rare interesting circumstances it could be legit, but what's the likelihood of that?
 
Old 07-02-2006, 11:37 PM   #6
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What is the point of spam if it is just random garbage? I thought spam was a method of cheaply advertising products. How can you sell a product if people can't understand what you are saying?
 
Old 10-31-2006, 07:38 AM   #7
heightdeprived
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Quote:
Originally Posted by General
What is the point of spam if it is just random garbage? I thought spam was a method of cheaply advertising products. How can you sell a product if people can't understand what you are saying?
It is the same problem we're currently experiencing. Our spam filter is not able to filter out the same spam messages we are recieving composed of random words and phrases without meaning. It serves the purpose of advertising by embedding a GIF image that shows the supposed content of the mail which, through the same method defeats bayesian learning in the spam filter and due to those random words the spam filter allows it to pass through

Quote:
Originally Posted by taylor_venable
Most of the spam I get are composed of random words. I don't understand it either; but SpamAssassin has flagged every single one of them, so I don't have to read them. I guess that ISPs aren't as good catching this type of spam because it requires more complicated checking; it's not just a simple easy-to-spot advert. So to avoid wasting resources they probably just run the most basic tests and then send it on. I can aford a little more CPU time for SpamAssassin because there's not many users on my mail system.

What mystifies me is when I get spam via the ISP that has a subject like "Re: i l0v3 u", a blank body, and a JPEG image attachment. Sure, in rare interesting circumstances it could be legit, but what's the likelihood of that?
Can you give us an idea how you are able to filter out spam messages coming from randomly generated e-mail addresses and containing meaningless text inside?
 
Old 11-01-2006, 12:46 AM   #8
heightdeprived
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up! up!

up up up!!!!
 
Old 11-01-2006, 03:11 AM   #9
dasy2k1
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yeh i have the same crud coming through, thankfully gmail recognises it as spam.... so it dousnet botehr me too much
Quote:
Custom sectionadd will contain all in Delete section Edit a standard Drag rearrange page a Click editadd headlines is only Reset.
Hasten security buildup abc Onlinethe age los Angeles san or Financial is urges Govt a lift Jaffna agocolombo oct ap or sri Lankas separatist in rebels lambasted government a not agreeing.
Strategy or Supply Chain Training of Warehouse Within Days is Since Yesterday Type am Fulltime Contractor Parttime Intern Success many employers dont make sure you maintain privacy am choose.
this one had a gif image trying to get me to buy a particuliar stock.....

most of the rest of the spam is trying to get me to invest in some company
 
Old 11-01-2006, 04:54 AM   #10
heightdeprived
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it's the very same e-mail we're receiving, though one of my peers sent me some rules I'll have it tested and I'll be informing you guys of what the result is. Btw, I have tried, appending reject_sender_login_mismatch rule in the main.cf and it looks like it helped though it wasn't able to completely eliminate spam mails but it was able to reduce the amount of spam messages in the mail queue, i just don't know if spam mail was reduced due to the fact that it's a non-working holiday today but it's under observation and I'll post what's up in it.....

Last edited by heightdeprived; 11-01-2006 at 05:01 AM.
 
Old 11-01-2006, 05:05 AM   #11
alienux
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Quote:
Originally Posted by jschiwal

Here is one of seven lines from some spam that I received:
too happy but coat tongue must awake. are war the sort monkey as clean. and tooth but taste garden too stick. as smile must meeting

The rest of the lines are similar. An eliza<->zippy the pinhead dialog would make more sense. Apparently, the spam filter only uses lexical and statistical analysis. It would be nice if they would be able to spot when messages sent from the same place make no sense. A little AI please!

I don't understand what the purpose of sending such a message is, other than to use up bandwidth on the network. Are these people mentally ill?
Quote:
Originally Posted by taylor_venable
Most of the spam I get are composed of random words. I don't understand it either
Quote:
Originally Posted by General
What is the point of spam if it is just random garbage?
The random words you see in Spam messages are Bayesian poisoners. Hardware-based Spam filters, such as the Barracuda Spam Firewall or SurfControl, allow you to create a database of items that are "Spam" or "Not Spam" so that they can better detect and block/allow mail based on your particular organization. This database is called a Bayesian Database.

The random words are designed to make your Bayesian Database less effective by polluting it with random words and phrases that make the database less effective, thus letting more Spam through. That's why its important not to add any Spam messages with poisoners to a Bayesian Database, even though it is actually Spam.
 
Old 11-01-2006, 05:14 AM   #12
heightdeprived
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amen to that, aside from random words/sentences/phrases, the e-mail addresses are also scrambled like qefqdadsfe@mydomain.net I wonder how it can be eliminated...
 
Old 11-03-2006, 09:50 PM   #13
ultranet
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I m new here saying hi to all in this thread
 
Old 11-06-2006, 02:52 AM   #14
dasy2k1
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Quote:
Originally Posted by ultranet
I m new here saying hi to all in this thread
Funny that pointless spam posting seems to gravatate to threads about SPAM
 
  


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